The Ohio State University
Co-Authors: Margaret Kalcic, Robyn Wilson, Douglas Jackson-Smith, and Jay Martin
Watershed modeling studies, including those of the Maumee River watershed, have found that targeting agricultural best management practices (BMPs) to fields with the highest nutrient loadings is more effective than randomly placing BMPs in reducing watershed-scale nutrient losses. However, farmers who manage these high nutrient-loss fields may not be the most willing to adopt BMPs. This study seeks to understand how targeting BMP placement by farmers’ willingness to engage in conservation practices, represented by a conservation identity proxy, affects nutrient loading from the Maumee River watershed as compared to the targeting of BMPs to fields with the highest nutrient loadings. To analyze the effect of targeting BMP placement by a farmer’s willingness to adopt a BMP, county-level distributions of farmer conservation identities, derived from farmer surveys completed in the watershed were embedded into a field-scale SWAT model of the Maumee River watershed. Results from this study indicate that targeting subsurface nutrient application and the adoption of buffer strips to fields with higher phosphorus losses lead to a faster reduction rate of phosphorus discharged from the watershed than by targeting these practices to fields managed by farmers with higher conservation identities. When targeting subsurface nutrient application and buffer strips to the 60% of fields with the highest rates of total phosphorus (TP) losses, spring TP losses decreased 27% and 17%, respectively, while spring Dissolved Reactive Phosphorus (DRP) losses decreased 35% and 12%, respectively. When targeting subsurface nutrient application and buffer strips to the 60% of fields managed by farmers with the highest conservation identities, spring TP losses decreased 19% and 10%, respectively, while spring DRP losses decreased 28% and 8%, respectively.